1. Field of the Invention
The present invention relates to an electrodeposition process and particularly to an electrodeposition process suitable for large scale production of titanium or titanium alloy. The present invention also relates to an electrodeposition apparatus for carrying out the process.
2. Description of the Prior Art
To electrodeposit titanium or the like, we or our assignees have proposed various processes, such as disclosed in Japanese Pat. No. 726,754 and Japanese patent application Nos. 107500/1974, 131960/1974 and 65920/1976, wherein a fused salt electrolytic bath is used so that a metal or alloy is grown by electrodeposition with the surface of the deposit being kept flat, thereby obtaining a smooth and compact electrodeposit having a desired thickness. Particularly in Japanese patent application No. 131960/1974, we have proposed an electrodeposition process for obtaining a smooth and compact electrodeposit, in which solid particles are dispersed in a fused salt electrolytic bath so as effectively to act on an electrodeposition surface and enable stable electrodeposition to be maintained for a long period of time. The solid particles used in this process are normally powdery particles consisting of silicon dioxide, carbon or the like, which are either fed into the bath from outside, or are constituent salt particles deposited from the fused salt electrolyte.
However, when solid particles are fed into the bath from outside, the particles may be contaminated with impurities or oxidized, and cause a deterioration in the quality of the electrodeposit to occur or difficulties in maintaining the electrolysis over a prolonged period of time. When salt particles deposited from the fused salt electrolyte itself are used as the solid particles, these problems do not occur. In this case, however, there are difficulties in obtaining controlled deposition of salt particles, in particular of the required amount and particle size, stably and continuously in the fused salt electrolytic bath.